Good and evil.

For me, good and evil are creation and destruction. If someone does something bad to you, they destroy your plan or the integrity of your bodies (this refers not only to the physical body, but also to the etheric, astral, mental, and other bodies). If a girl loves you, she creates love and harmony, which helps you to act more productively, and even the birth of children is creation... but if everything was only created and nothing was destroyed, it would be a disaster, and therefore evil is also important and necessary (not to mention good...).